\begin{figure}[H]
\centering
\figscale{
  \begin{tikzpicture}[%
    >=stealth,
    shorten >=1pt,
    node distance=2cm,
    on grid,
    auto,
    state/.append style={minimum size=2em},
    thick,
    scale=0.4
  ]
    \node[state, rectangle, align=center] (N1) {$A$\\$AX(EX(EX(\$E)))$};
    \node[state] (N2) at (-4, -4) {$B$};
    \node[state] (N3) at (4, -4) {$C$};
    \node[state] (N4) at (0, -8) {$D$};
    \node[state] (N5) at(4, -8) {$E$};

\path[->]
	(N1) edge node [above left, pos=0.75] {$EX(EX(\$E))$} (N2)
	(N1) edge node [above right, pos=0.75] {$EX(EX(\$E))$} (N3)
	(N2) edge node [below left, pos=0.25] {$EX(\$E)$} (N4)
	(N3) edge node [below right, pos=0.25] {$EX(\$E)$} (N4)
	(N4) edge node [below] {$\$E$} (N5);
  \end{tikzpicture}
}
\caption{Affichage de la preuve pour $AX(EX(EX(\$E)))$}
\label{fig:PreuveAffichageDot4}
\end{figure}